CAJ | 학술논문

拟布氏乳杆菌K1（ Lactobacillus parabuchneri K1）在厌氧条件下可以有效转化果糖生成甘露醇。但当果糖浓度逐步升高时，菌体生长及甘露醇产生速度减慢。为了提高K1菌株在高浓度果糖条件下的生长及转化速率，设计了定向富集耐渗突变株的实验，采用10 L发酵罐，在高渗条件下连续转接培养，培养过程中果糖质量浓度经4次梯度增加，从270 g／L增加到300 g／L。经55 d传代培养后分离纯化，获得耐渗突变株K2。通过2 L发酵罐验证试验，发现K2菌株在300 g／L果糖条件下，果糖利用速率提高103％，发酵周期缩短46?4％，甘露醇的平均产量达到189 g／L，达到理论转化率的94?0％。
의포씨유간균K1（ Lactobacillus parabuchneri K1）재염양조건하가이유효전화과당생성감로순。단당과당농도축보승고시，균체생장급감로순산생속도감만。위료제고K1균주재고농도과당조건하적생장급전화속솔，설계료정향부집내삼돌변주적실험，채용10 L발효관，재고삼조건하련속전접배양，배양과정중과당질량농도경4차제도증가，종270 g／L증가도300 g／L。경55 d전대배양후분리순화，획득내삼돌변주K2。통과2 L발효관험증시험，발현K2균주재300 g／L과당조건하，과당이용속솔제고103％，발효주기축단46?4％，감로순적평균산량체도189 g／L，체도이론전화솔적94?0％。
Lactobacillus parabuchneri K1 can effectively convert fructose to mannitol under anaerobic conditions. However, as fructose concentration increases, cell growth and the yield of mannitol decrease. A directed mutation experiment was designed to improve the cell growth rate and the conversion of L?parabuchneri K1 at high fructose concentration. A 55?day continuous subculture was conducted using a 10?L fermenter with four?time gradient increasing fructose concentration from 270 to ultimate 300 g/L. L?parabuchneri K2, a mutant resistant to high osmotic pressure, increased fructose consumption by 103% in a 2?L fermenter at 300 g/L fructose. Fermentation period was shortened by 46?4% comparing with the K1 strain?The mannitol yield was reached to 189 g/L, 94?0% of theoretical conversion.